The present invention relates to a method and apparatus for providing a convenient, time-saving and economical means for axially aligning the ends of pipes such as pile casings to permit the pile casings to be welded together during a pile driving operation.
During a pile driving process, as a first pile is driven into the ground, a second pile or add-on is suspended vertically above the first by means of a crane or the like, and lowered onto the projecting end of the first pile. The ends of the two piles must be accurately aligned so that they can be welded together around their seam line. Due to the size and mass of the pile casings, alignment of their ends is often a difficult process, and as a result, unnecessary amounts of time are often wasted to accommodate alignment of the pipes.
Previously, the ends of the pile casings have generally been aligned manually without the aid of assisting devices. However, since the piles are usually suspended from booms and long cables or the like and are consequently unstable and because they are massive, this is an awkward and time-consuming task. Chill rings or sleeves are sometimes secured within the upper end of the lower pipe casing and project out of this end to provide a means for preventing shifting of the ends of the casings once they have been properly aligned. Chill rings do not function, however, to provide a means for aligning the ends of the pile casings, and in the event the casings are misaligned when the pile casings are brought together, the weight of the upper casing will frequently drive the chill ring into the lower casing and make it useless.